How Does a Lack of Sleep Affect Your Mood?

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How well you sleep has a lot to do with how you feel the next day. A rough night of sleep could make you feel fatigued, drowsy or that it’s harder to accomplish simple tasks. Not getting enough sleep has more effects on your well-being than just physical drawbacks. 

In this article, I’ll review what a lack of sleep looks like and how it affects different aspects of your mood. I’ll also go over how you can get a better night of sleep so you can wake up on the right side of the bed.

[Editor’s Note: The content provided on this site is for general informational purposes only. Any information provided is not a substitute for professional medical advice. We encourage you to consult with the appropriate health expert if you have concerns.]

Lack of Sleep

There are a lot of reasons why people lose sleep at night. And unfortunately, it’s all too common for people to lose sleep on a regular basis. According to the CDC, about one-third of adults get less than the recommended amount of sleep per night. 

Before I explain the link between lack of sleep and your mental well-being, I’ll go over what sleep deprivation is, its common causes and how much sleep you should get to feel your best. 

What is Sleep Deprivation?

Sleep deprivation is a condition that results from not getting enough sleep. It is the short- and long term effects of receiving fewer hours of sleep than you require to function, which depends on a few factors. Sleep deprivation can also be considered either short- or long-term depending on how many nights you miss hours of sleep.

There’s a good chance that you are already familiar with the most common symptoms of sleep deprivation. The telltale sign that you are sleep deprived is if you feel excessively sleepy throughout the day. Other symptoms of sleep deprivation include:

  • Excessive yawning
  • Forgetfulness
  • Trouble focusing
  • Low energy level
  • Headaches
  • Short attention spans
  • Decreased performance at work
  • Increased irritability and other mood changes

Over time, these symptoms can impair your overall health and quality of life. The chronic effects of sleep deprivation include having an increased risk of high blood pressure, heart disease and a weakened immune system. 

Learn more in our complete guide to sleep deprivation

What Causes Sleep Deprivation?

Sleep deprivation could be caused by a variety of factors. While some are out of our control, others can be managed to help prevent the negative effects of losing sleep. 

Health Factors

Sleep deprivation is not a disorder itself, but it could be a symptom of a sleep disorder or related to another condition. Here is a list of some conditions that are associated with sleep deprivation:

  • Insomnia is a condition that makes it difficult for people to fall asleep or stay asleep. People with insomnia are less likely to get the recommended seven to nine hours of sleep per night. 
  • Narcolepsy is a sleep disorder in which the brain struggles to regulate the body’s sleep-wake cycle. Many people with narcolepsy experience interruptions while sleeping at night. 
  • Sleep Apnea causes people to briefly stop breathing while they sleep, and many people with this condition may wake up momentarily without realizing it. This prevents them from getting restful sleep and feeling refreshed the next day. 
  • Restless Leg Syndrome (RLS) is the strong urge to move or stretch your legs. People with this condition often have difficulty falling asleep and staying asleep. 
  • Chronic Pain is often accompanied with sleep disruptions and inflammation. And sometimes, medications used to treat chronic pain can reduce sleep duration. 

Lifestyle Factors

Busy schedules can make it difficult to get enough sleep at night.Whether it is because you are a parent with young kids, a college student with several upcoming assignments or someone who works late shifts, these responsibilities can prevent you from getting enough sleep. People juggling extra responsibilities are also more likely to lose sleep due to stress or anxiety. 

Besides hectic schedules, some lifestyle choices can be detrimental to getting quality sleep at night. For example, staying out late at a party or binge-watching shows can deprive people of key hours of sleep. 

Environmental Factors

Poor sleep hygiene and lousy sleep environments can make it difficult to fall asleep. Ideally, the place where you sleep is dark, quiet and cool. Not having a comfortable place to sleep, or having too much light or noise could lead to deficient sleep. 

How Much Sleep Do You Need? 

The amount of sleep you need depends on your age and life circumstances. People typically need fewer hours of sleep as they get older. But if you have lost sleep from traveling or you recently pulled an all-nighter, you may need to sleep more hours over one or several days to recover from sleep debt. You may also need to sleep more than the recommended amount for your age if you are pregnant or sick. 

Here’s a closer look at the CDC’s recommendations:

To know how many hours of sleep you are getting per night, try using a sleep tracker like the Oura ring or RISE Science App.

Sleep Deprivation & Mood

Sleep and mental health rely on one another—when one isn’t functioning properly, the other suffers as well. Keep reading to learn how lack of sleep could impact your mood and how your mental health can impact your quality of sleep. 

How Mood Impacts Sleep

Existing mental health conditions or emotional distress can make it more difficult to get seven to nine hours of sleep. Insomnia, sleep disturbances or feeling fatigued are symptoms of psychiatric disorders such as depression, anxiety, obsessive compulsive disorder (OCD), post-traumatic stress disorder (PTSD), schizophrenia and psychological stress. One study found that almost 50% of insomnia cases are related to a mental disorder. 

Because mental illness can affect people in a variety of ways, the means that mental health impacts sleep patterns is not the same for everyone. For example, depression may cause someone to sleep poorly and feel fatigued during the day. But other people with depression might oversleep, which is also linked to poor health. 

The reasons why mood and mental health disorders keep someone from falling or staying asleep vary by condition. Dealing with panic attacks and anxiety often keep someone awake at night longer from racing thoughts. Those with PTSD might struggle with waking up in the middle of the night from disturbing nightmares associated with traumatic life events. Physical manifestations of stress such as headaches, muscle tension and gut issues can also make it difficult to fall asleep. 

How Lack of Sleep Impacts Mood

The relationship between mood and sleep is bidirectional, which means both influence each other. A lack of sleep can make you feel moody or irritable the same way a bad mental headspace can make it hard to sleep. Poor sleep can impact your mood and mental health in the following ways:

Emotion Regulation 

Emotion regulation refers to our ability to effectively manage how we experience and express emotions. When you are unable to regulate your emotions, it becomes easier to become overwhelmed and make emotional decisions. It’s also common to experience mood swings. Being well-rested is essential to coping with difficult emotions or difficult life circumstances. 

Several studies have shown that when you are sleep deprived, it is common to feel angry, depressed and or anxious. A 2021 study found participants who received less than six hours of sleep per night were two and a half times more likely to have frequent mental distress than participants that slept more than six hours. Sleep disturbances or shorter sleep duration is also linked to worsening symptoms of psychiatric disorders. 

Social Interactions and Relationships

Sleep deprivation and relationship conflicts often go hand in hand. A 2014 study suggests that sleep deprived people had lower amounts of emotional empathy than people who received at least seven hours of sleep. Whenever you are sleep deprived, you are less likely to resolve conflicts and make rational decisions about your relationships.

There is also an observed feedback loop between lack of sleep and loneliness. A 2018 study found that sleep deprived people withdraw themselves from social interaction. Loneliness also raises our stress hormone levels, which in turn makes it difficult to fall asleep. This loop continues until a person is no longer sleep deprived or no longer feels lonely. 

Cognitive Functions

According to the American Psychological Association (APA), cognitive function refers to performance of the mental processes of learning, perception, reasoning and much more. Sleep deprivation affects your ability to concentrate, recall your short-term memory and maintain decision-making skills. A lack of sleep also affects your awareness and judgment of things around you, which goes hand in hand with poor emotion regulation skills. It also greatly affects your alertness, which can lead to dangerous drowsy driving

How to Get a Better Night’s Sleep

Lack of sleep can take a toll on your physical and mental well-being. The best way to get more sleep at night and prevent sleep deprivation is to practice healthy sleep habits. These are a few ways to help you fall asleep and stay asleep longer. 

RELATED: What to Do If You Can’t Sleep

Consistent Bedtime Routine

If you have trouble falling asleep at night, try creating a consistent bedtime routine. The goal is to form relaxing habits an hour or two before bedtime to soothe your mind and body before you get into bed. 

Whatever you find most relaxing is up to personal preference. Removing your makeup or washing your face, putting on comfortable pajamas and meditating are all great ways to prepare yourself for bed. During your bedtime routine, try to limit your exposure to blue light from computer or phone screens or doing activities that increase your energy level. 

Sleep Environment

As I mentioned previously, there are several environmental factors that can cause a lack of sleep. Ideally, there are as few distractions like lights, sounds and devices around you as possible. Blackout curtains and white noise machines can help manage disturbances and promote more restful sleep. 

Invest in a Great Mattress

Sleeping on the wrong mattress can make it difficult to fall asleep and stay asleep. There is not one best mattress that is suitable and comfortable for all sleepers. The best mattress for you mainly depends on your feel preferences, body type and sleeping position. 

If you are constantly waking up fatigued or in pain, you might not be sleeping on the right mattress. Check out our Ultimate Mattress Buying Guide to know what to look for in a new mattress. 

RELATED: Best Mattresses of 2024

Avoid Caffeine Before Bed

Caffeine is a stimulant that can help people stay awake if they have low energy or feel fatigued. So caffeine should be avoided several hours before you go to bed. Otherwise, you’ll feel an extra surge of energy when you are supposed to be winding down to sleep. 

Using caffeine to delay your sleep schedule tends to lead to a feedback loop where you become dependent on it to stay alert during the day. 


Everyone knows that exercise is important to maintain good health, but did you know regular exercise is also key for maintaining a consistent sleep schedule? Researchers at Johns Hopkins Medicine have confirmed that certain types of exercise can help you fall asleep faster and stay asleep longer. 

Moderate aerobic exercise has been shown to increase the amount of “slow wave” or deep sleep a person gets per night. Deep sleep is the most restorative stage of sleep and is vital to cognitive function when you are awake. Exercise is also linked to stabilizing mood and relaxing the mind, which make drifting off to sleep easier. 

RELATED: What’s the Link Between Sleep and Exercise?


Can a lack of sleep cause headaches?

Yes, one sign you are sleep deprived is that you wake up with headaches or you experience headaches in the morning. The fewer hours you sleep, the less time you spend in deep sleep, the most restorative sleep stage. One study found that a lack of deep sleep lowers your pain threshold to painful tension headaches.

Is it okay to get five hours of sleep?

The CDC recommends adults receive between seven and nine hours of sleep every night. Sleeping five hours at night will eventually lead to symptoms of sleep deprivation including fatigue, irritability and drowsiness. Chronic sleep deprivation is linked to numerous physical and mental health issues including depression, heart disease and obesity. 

What are signs you are sleep deprived?

The main sign that you are sleep deprived is if you feel excessively sleepy throughout the day. Other signs that you are not getting enough sleep are if you feel moody or are having mood swings, performing poorly at work, having trouble concentrating or have poor memory and if you have frequent headaches.

How do you fix sleep deprivation?

The best way to sleep more at night is to create a healthy bedtime routine. This includes avoiding caffeine, alcohol and blue light before bed. It’s also key to create an ideal sleep environment with a comfortable mattress. Sleep in a dark, quiet and cool room and eliminate as many distractions as possible.

Celeste Parler

Celeste is an editorial intern for Mattress Clarity and a current senior at Texas State University studying digital media innovation. After graduating in December 2023, she hopes to work in the realm of content marketing and SEO and become a content creator. In her spare time, she enjoys supporting local musicians and watching reality TV.